#include<stdio.h>
#include<stdlib.h>
#include<fcntl.h>
#include<errno.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<unistd.h>

int main(int argc,char **argv){

    if(argc < 2){
        fprintf(stderr,"Usage %s sourcefile",argv[1]);
        exit(1);
    }

    int fd = open(argv[1],O_WRONLY|O_CREAT|O_TRUNC,0600);
    if(fd < 0){
        perror("open()");
        exit(1);
    }

    off_t offt = lseek(fd,5LL*1024LL*1024LL*1024LL-1LL,SEEK_SET);
    // off_t offt = lseek(fd,5LL*1024LL*1024LL*1024LL,SEEK_SET);
    printf("%lld",offt);

    write(fd,"",1);

    close(fd);

}